CN1196123C - Optical-head device - Google Patents
Optical-head device Download PDFInfo
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- CN1196123C CN1196123C CNB01122360XA CN01122360A CN1196123C CN 1196123 C CN1196123 C CN 1196123C CN B01122360X A CNB01122360X A CN B01122360XA CN 01122360 A CN01122360 A CN 01122360A CN 1196123 C CN1196123 C CN 1196123C
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- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
- G11B7/12—Heads, e.g. forming of the optical beam spot or modulation of the optical beam
- G11B7/135—Means for guiding the beam from the source to the record carrier or from the record carrier to the detector
- G11B7/1381—Non-lens elements for altering the properties of the beam, e.g. knife edges, slits, filters or stops
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- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
- G11B7/12—Heads, e.g. forming of the optical beam spot or modulation of the optical beam
- G11B7/125—Optical beam sources therefor, e.g. laser control circuitry specially adapted for optical storage devices; Modulators, e.g. means for controlling the size or intensity of optical spots or optical traces
- G11B7/127—Lasers; Multiple laser arrays
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- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
- G11B7/12—Heads, e.g. forming of the optical beam spot or modulation of the optical beam
- G11B7/135—Means for guiding the beam from the source to the record carrier or from the record carrier to the detector
- G11B7/1362—Mirrors
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- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
- G11B7/12—Heads, e.g. forming of the optical beam spot or modulation of the optical beam
- G11B7/135—Means for guiding the beam from the source to the record carrier or from the record carrier to the detector
- G11B7/1365—Separate or integrated refractive elements, e.g. wave plates
- G11B7/1367—Stepped phase plates
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- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
- G11B7/12—Heads, e.g. forming of the optical beam spot or modulation of the optical beam
- G11B7/135—Means for guiding the beam from the source to the record carrier or from the record carrier to the detector
- G11B7/1395—Beam splitters or combiners
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- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
- G11B2007/0003—Recording, reproducing or erasing systems characterised by the structure or type of the carrier
- G11B2007/0006—Recording, reproducing or erasing systems characterised by the structure or type of the carrier adapted for scanning different types of carrier, e.g. CD & DVD
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- Optics & Photonics (AREA)
- Optical Head (AREA)
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- Diffracting Gratings Or Hologram Optical Elements (AREA)
Abstract
Provided is a small and inexpensive optical element for light guiding for a double wavelength optical head device used for aligning the optical axis of each laser beam and guiding each laser beam to a common photodetector. The optical element (5) to guide a first and second laser beams (L1) and (L2) whose optical axes are deviated to the common photodetector (3) consists of a resin molding and provided with a discoid main body (51), an incident plane (52) formed so as to have one stepped surface and a flat light-emitting surface (53) perpendicular to an optical axis (5a) formed on the other surface. The difference in level of the adjacent stepped surface (54) which constitutes the stepped surface of the incident plane (52) is one wavelength of optical path difference only when a return laser beam (Lr1) passes. The return laser beam (Lr1) passes the element (5) without being deflected in the traveling direction. A return laser beam (Lr2) is deflected at a prescribed angle when passing the optical element (5) for light guiding, and condensed on the same position as that of the return laser beam (Lr1) on the common photodetector.
Description
Technical field
The present invention relates to the record of CD (compact disk) and DVD optical recording medias such as (digital video disks), the employed dual wavelength optical-head apparatus of resetting.In more detail, relate to employed leaded light optical element in such dual wavelength optical-head apparatus, described leaded light is used for making the relative angle of the light of the different wave length that penetrates from the light source of diverse location luminous point to change with optical element, the optical axis of these light is merged, perhaps these light are guided to shared photo detector.
Background technology
As optical recording media, known to CD and DVD and so on substrate thickness and recording density recording medium inequality, for these recording mediums are carried out recording of information and playback, must use different wavelength of laser.For example, the playback of DVD needs the laser of 650nm wavelength, and CD-R is because of low at the reflectivity of 650nm wavelength band, so its playback and record need the laser with the 780nm wavelength.
Therefore, as the optical-head apparatus that the playback of recorded of the playback of carrying out DVD and CD-R is used, known have a kind of be equipped with LASER Light Source that penetrates the 650nm wavelength laser and the device that penetrates the LASER Light Source of 780nm wavelength laser, and it is called as the dual wavelength optical-head apparatus.For example, in the open communique of Japanese patent of invention 1996 No. 55363, such dual wavelength optical-head apparatus is disclosed.
Such dual wavelength optical-head apparatus is in order to realize the requirement of small compact, and the optical system of each laser is shared.For this reason, will pass through common object lens focusing on optical recording media from the laser aimings that penetrate, that luminous point is different of each LASER Light Source to common light path with optical splitter.In addition, with the reflected light of common photo detector detection from optical recording media.
But the optical splitter that uses for multi-stripe laser is guided to common light path must reflect a certain laser and makes another laser-transmitting, thereby merges light path.In order to read information through object lens and will to make on the point of laser focusing in diffraction limit, the corrugated aberration is worsened for the laser that sees through optical splitter.Therefore, as optical splitter, the general optical splitter that uses the prism formation of cube type.But such optical splitter costs an arm and a leg, and is unfavorable for reducing manufacturing price.
In addition, when using common photo detector, must carry out the three-dimensional position adjustment respectively to two LASER Light Source of configuration respectively, will penetrate after the reflected light of optical recording media reflection gathers one from these light sources with respect to common photo detector.Therefore, there is the problem that causes adjusting cost raising and reliability decrease.
Summary of the invention
Problem in view of above prior art existence, problem of the present invention is, in optical-head apparatus with a plurality of light sources that penetrate different wavelengths of light, provide a kind of that use for the optical axis that makes each light beam that penetrates from each light source merges, can the cheap leaded light optical element of making.
In addition, problem of the present invention is, in the optical-head apparatus with a plurality of light sources that penetrate different wavelengths of light, provides a kind of and uses in order to be guided to shared photo detector by each light beam after the optical recording media reflection, can the cheap optical element of making.
Also have, problem of the present invention is, by use this can the cheap leaded light optical element of making, a kind of optical-head apparatus that can cheap make optical system, also can adjust easily when assembling is provided.
In order to address the above problem, leaded light optical element of the present invention, be to be used for making in the optical-head apparatus optical axis of the different wavelengths of light that penetrates from each light source to merge, or be used for these light is guided to shared photo detector, it is characterized in that, this leaded light has the relative plane of incidence and exit facet with optical element, one of the described plane of incidence and exit facet are stepped surfaces, the level difference size of each adjacent stations terrace of this stepped surfaces is set at, only, make it produce n wavelength amount (n=1 to through a kind of wavelength light among the described different wavelengths of light of these adjacent stations terraces, 2,3 ...) phase differential.
The a kind of wavelength light that sees through leaded light with optical element of the present invention is because be the integral multiple of wavelength by the phase differential of this light component behind each step surface, so the corrugated skew can not take place.Therefore, this light working direction can not change, and generates the corrugated when inciding the plane of incidence, and penetrates from exit facet.And other different light of wavelength, after using each step surface of optical element by leaded light, the phase deviation between its light component is not the integral multiple of wavelength, so the corrugated also is offset.Therefore, penetrate from exit facet behind the working direction deflection certain angle of this light.So by making light transmission leaded light optical element of the present invention, the relative angle of each light beam working direction just changes, the optical axis of these light is merged, perhaps these light are guided to shared photo detector.
Here, be under the situation of divergent beams or converging beam at described each light beam, preferably leaded light of the present invention is made curved surface with the described step surface of optical element.
In addition, when described step surface is made concentric circles, form with described step surface and to compare when parallel, its advantage is to reduce the error of the optical axis rotation in optical system.
The present invention is a kind of optical-head apparatus with leaded light of above-mentioned formation with optical element, have: the 1st light source that penetrates the 1st bundle light, penetrate the 2nd light source of the 2nd bundle light different with described the 1st bundle light wavelength, make the described the 1st and the 2nd bundle light focus on object lens on the record surface of optical recording media, and by the shared photo detector of described object lens acceptance by the 1st and the 2nd bundle light of the record surface reflection of optical recording media, described leaded light with the optics arrangements of components on from described object lens to the light path of described shared photo detector, make by after the deflection of one of the bundle of the described the 1st and the 2nd after the reflecting surface of optical recording media reflection light, this two-beam is guided to described shared photo detector.
Here, also can with described leaded light with the optics arrangements of components from described the 1st light source and described the 2nd light source to the light path of described object lens, the described the 1st and the 2nd bundle light be at optical axis guide to described object lens under the consistent state.
On the other hand, in optical-head apparatus of the present invention, simplify, preferably the described the 1st and the 2nd light source is made the combined light source that is contained in the common components, replace the independent separately light source that is provided with for the position adjustment that makes optics between each light source and the shared photo detector.
Description of drawings
Figure 1 shows that the simple pie graph of the optical-head apparatus optical system of using the present invention the 1st embodiment.
Be respectively the local amplification profile of leaded light shown in Figure 1 shown in Fig. 2 (a) and (b), (c) with plane of incidence side plan view, its outboard profile and the plane of incidence section shape of optical element.
Fig. 3 (a) and (b) are respectively explanation and see through leaded light among Fig. 2 with the deflect key diagram of principle of the laser of optical element.
Fig. 4 (a) and (b) are respectively plane of incidence side plan view and the sectional view of leaded light shown in Figure 1 with the other example of optical element.
Figure 5 shows that the sectional view of another example of step surface that forms with the plane of incidence of optical element at the leaded light of Fig. 1.
Be respectively the sectional view of leaded light shown in Figure 1 shown in Fig. 6 (a) and (b) with two other example of optical element.
Figure 7 shows that the simple pie graph of the optical-head apparatus optical system that application the present invention the 2nd embodiment relates to.
Embodiment
Following with reference to accompanying drawing, illustrate to have the dual wavelength optical-head apparatus embodiment of leaded light of the present invention with optical element.
Figure 1 shows that the simple pie graph of optical system of the dual wavelength optical-head apparatus of present embodiment.This routine optical-head apparatus 1 is that substrate thickness such as CD, CD-R, DVD and recording density multiple optical recording media 6 inequality are carried out information playback, recording device, have double-wavelength light source (combined light source) 10 and optical system shared Lo, described double-wavelength light source 10 in common components 13, be equipped with wavelength that ejaculation represents with solid line be 650nm the 1st laser L1 the 1st LASER Light Source 11 and to penetrate the wavelength that dots be the 2nd LASER Light Source 12 of the 2nd laser L2 of 780nm.The luminous point position of the 1st laser L1 and the 2nd laser L2 is for example at a distance of about 110 μ m.
Dispose among the optical system shared Lo: in order to generate tracking error signal, will to be separated into 3 bundle diffraction of light gratings 20 from the 1st laser L1 and the 2nd laser L2 that double-wavelength light source 10 penetrates, to be divided into the laser L1 of 3 bundles behind the light, the tabular optical splitter 30 of L2 partial reflection, make by the laser L1 after this optical splitter 30 reflection, the collimation lens 40 that L2 becomes directional light, and make the laser L1, the L2 that penetrate from collimation lens 40 focus on object lens 41 on the record surface 6a of optical recording media 6.
In addition, optical system shared Lo disposes shared photo detector 3, is used to accept by the record surface 6a of optical recording media 6 reflection back, by the 1st laser L1 of optical splitter 30 and back light Lr1, the Lr2 of the 2nd laser L2.Between optical splitter 30 and photo detector 3, the back light Lr1, the Lr2 that dispose light shaft offset guide to the leaded light optical element of using on the shared sensitive surface of shared photo detector 35.This leaded light is narrated in the back with the structure of optical element 5.
In this example, make the optical axis of the 1st laser L1 that penetrates from the 1st LASER Light Source 11 consistent with the systematic optical axis 41a (optical axises of object lens 41) of optical-head apparatus 1.Therefore, the 2nd laser L2 that penetrates from the 2nd LASER Light Source 12 passes through optical system shared Lo with the state that departs from optical axis.
In the optical-head apparatus 1 of this formation,, penetrate the 1st laser L1 of wavelength 650nm from the 1st LASER Light Source 11 when from the time as the DVD playback information of optical recording media 6 etc.The 1st laser L1 is directed to optical system shared Lo, on the DVD record surface, be focused into luminous point by object lens 41,, focused on the shared photo detector 3 through optical splitter 30, leaded light optical element 5 by the back light Lr1 of the 1st laser L1 after the reflection of DVD record surface.The signal that utilizes shared photo detector 3 to measure carries out the information playback of DVD etc.
And when from as the CD-R playback information of optical recording media 6 etc. the time, penetrating wavelength from the 2nd LASER Light Source 12 is the 2nd laser L2 of 780nm.The 2nd laser L2 also is directed to optical system shared Lo, on the record surface of CD-R, be focused into luminous point by object lens 41,, focused on the shared photo detector 3 through optical splitter 30, leaded light optical element 5 by the back light Lr2 of the 2nd laser L2 after the reflection of the record surface of CD-R.The signal that utilizes shared photo detector 3 to measure carries out the information playback of CD-R etc.
(leaded light optical element)
Here, because the optical axis of the 1st LASER Light Source 11 and the 2nd LASER Light Source 12 departs from configuration, so if keep departing from state, the light receiving position of the back light Lr2 that then shared photo detector 3 receives also can depart from the light receiving position of back light Lr1.Adopt leaded light to revise departing from of this light receiving position with optical element 5.
Fig. 2 (a) and (b) reach and (c) are depicted as the part expansion cut-open view of this routine leaded light with plane of incidence side vertical view, its side view and the plane of incidence section shape of optical element.Fig. 3 (a) and (b) are respectively explanation and see through leaded light shown in Figure 2 with the deflect key diagram of principle of the laser of optical element 5.
This routine leaded light is resin forming products with optical element 5, and is whole in the form of annular discs, and a face that is surrounded by its circular outer peripheral portion 51 is the plane of incidence 52, and another face is an exit facet 53.From Fig. 2 (c) as can be known, the plane of incidence 52 is that the direction along optical axis 5a has differential stepped surfaces, and this stepped surfaces is formed with substantially parallel a plurality of step surfaces 54 with certain width.On the other hand, exit facet 53 is tabular surfaces vertical with the optical axis 5a of this optical element.
This leaded light is made of such resin material with the material of optical element 5: it can see through the 1st laser and the 2nd laser, if the refractive index to the 1st Wavelength of Laser 650nm is n1, refractive index to the 2nd Wavelength of Laser 780nm is n2, n1=1.51862 for example then, n2=1.52196.
With reference to Fig. 3, to the plane of incidence 52 the level difference size describe.Adjacent downside step surface 541 is set at the differential D of upside step surface 542, when wavelength be the 1st laser L1 of 650nm when seeing through upside step surface 542 when seeing through downside step surface 541, two light paths can produce the poor of 1 wavelength (2 π) amount.That is, the optical path length OP1 (A) of the laser part L1A that sees through upside step surface 542 when seeing through the thickness of differential D among the 1st laser L1 when establishing wavelength 650nm and be λ 1, can be expressed as:
OP1(A)＝k1*n1*D
Wherein, k1=2 π/λ 1
In addition, the laser part L1B that sees through the downside step surface 541 adjacent with the upside step surface 542 light path OP1 (B) that arrives downside step surface 541 in the space of passing differential D part can represent with following formula:
OP1(B)＝k1*1*D
At this moment, to satisfy the condition that produces 1 wavelength (2 π) path difference between OP1 (A) and the OP1 (B) that makes because set differential D, so,
OP1(A)-OP1(B)＝k1*(n1-1)*D＝2π
If ask differential D, then be following formula:
D＝λ1/(n1-1)＝1253.3nm
If differential D is set at 1253.3nm, even phase places were offset after then the 1st laser L1 saw through the plane of incidence 52, the corrugated can not be offset yet, each differential corrugated that sees through strengthens mutually once more, generate original corrugated (the differential corrugated T that sees through that schematically shows with double dot dash line), even so penetrate from exit facet 53, working direction can not change yet.
The 2nd laser L2 below is described.The same path difference OPD2 that calculates optical path length OP2 (A) and optical path length OP2 (B), wherein light path OP2 (A) for the laser part L2A that sees through upside step surface 542 sees through the optical path length during differential D segment thickness, OP2 (B) is for seeing through the optical path length of laser part L2B till arriving downside step surface 541 behind the space of passing differential D part of the downside step surface 541 adjacent with upside step surface 542, if wavelength 780nm is λ 2, then path difference OPD2 can be expressed as:
OPD2＝OP2(A)-OP2(B)＝k2*(n2-1)*D
Here, because differential D be:
D＝λ1/(n1-1)
So,
OPD2＝2π*(λ1/λ2)*[(n2-1)/(n1-1)]
Wherein, k2=2 π/λ 2
λ1/λ2≠(n2-1)/(n1-1)≠1
So, path difference OPD2 ≠ 2 π
If differential D is set at 1253.3nm, then the 2nd laser L2 see through differential after, along with phase place is offset, the corrugated also is offset.Therefore, if differential the schematically showing with double dot dash line through the corrugated that for example laser L2A is seen through behind the higher level 542 is the differential corrugated S2 of seeing through, and laser L2B is seen through differential after the subordinate 541, and to see through that the corrugated also schematically shows with double dot dash line be the differential corrugated S1 of seeing through, and the then differential corrugated S2 of seeing through produces with the differential corrugated S1 of seeing through and is offset.Therefore, each of generation be differential to be seen through corrugated S1, S2 and with original corrugated variation has taken place, so if the 2nd laser L2 is from exit facet 53 ejaculations, working direction just deflects.In addition, the differential intensity of variation that sees through the corrugated can be adjusted by adjusting the level difference size.
In addition, differential D is so long as relative the 1st laser L1 produces integral multiple (2 π, 4 π of 1 wavelength (2 π) ...) size of phase differential gets final product.
Like this, the leaded light of the optical-head apparatus that this is routine is elements that the surface only forms differential shape with optical element 5, is suitable for producing in batches, can cheaply make.In addition, in this example, can be because do not use prism from the laser aiming of each light source to shared photo detector, so, the optical system compact can be made, and the cost of optical system can be reduced.Also have, in this example, because use the combined light source of dual wavelength, so, to compare with the light source that uses separate configurations, each light source is aimed at more convenient with shared photo detector optical position.
(leaded light another example of optical element)
Fig. 4 (a) and (b) are depicted as plane of incidence vertical view and the cut-open view of leaded light with another example of optical element.This routine leaded light is identical with leaded light shown in Figure 2 with optical element 5 with the basic comprising of optical element 5A.Difference is, on the plane of incidence 52, is formed with the step surface 54A of the certain width of concentric circles.
Under the situation of parallel each step surface of formation shown in Figure 2, the 2nd laser deflects to the relative vertical direction of each step surface.Therefore, if this leaded light is not high with the bearing accuracy of the sense of rotation of optical element relative system optical axis 41a, just the light after the deflection can not be guided to the light receiving position of the 1st laser on the shared photo detector.Different therewith is, under the situation of formation concentric circles step surface 54 shown in Figure 4, sees through the 2nd laser behind these step surfaces 54A towards the center deflection certain angle of these step surfaces 54A.Therefore, compare during with formation parallel block terrace, can suppress the positioning error of sense of rotation.
Also have, above-mentioned each leaded light is the step surface plane vertical with optical axis 5a with optical element 5 and 5A, but also it can be made convex surface or concave curved surface.Fig. 5 shows the example that the leaded light of making convex surface is used optical element.Even the 1st laser L1 and the 2nd laser L2 are converging beam or divergent beams, this leaded light also can make the relative angle of the 1st laser L1 and the 2nd laser L2 take place suitably to change with optical element 5B, guides on the shared photo detector
Leaded light two other example with optical element has been shown among Fig. 6.Leaded light optical element 5c shown in Fig. 6 (a), a face of its fuel plate body 501 be as the plane of incidence 502 of step profile, and another face is as the smooth exit facet 504 vertical with optical axis 503.In addition on the plane of incidence 502, overlapping have inequality overlapping 505 of refractive index and component body 501.This plane of incidence of overlapping 505 506 is made the tabular surface vertical with optical axis 503.Consequently, this routine leaded light is the element of rectangular section with optical element 5C integral body.
Leaded light optical element 5D shown in Fig. 6 (b) is formed with the plane of incidence 512 that stepped surfaces constitutes on the inclined-plane of the prism 511 of triangular cross-section, and smooth face that will be relative therewith is as exit facet 513.In addition, inequality overlapping 514 of overlapping refractive index and prism 511 forms smooth oblique incidence face 515 on the plane of incidence 512.
Under the situation of this leaded light with optical element 5C, 5D, the the 1st and the 2nd laser that penetrates from smooth exit facet 504,513 after these plane of incidence 506,515 incidents, by between laser part La, the Lb of this adjacent stations terrace, a certain laser is produced the path difference of 1 wavelength integral multiple.
(the 2nd embodiment)
In above-mentioned the 1st embodiment, leaded light is configured in from object lens 40 to photo detector with optical element 5 on 13 the light path.But also can not dispose like this, replace as shown in Figure 7, be configured in from the 1st LASER Light Source 11 and described the 2nd LASER Light Source 12 to the light path of optical splitter 30, this optical splitter 30 guides to object lens 41 with the 1st laser L1 and the 2nd laser L2.
In this case, with optical element 5 relative angle of the 1st laser L1 and the 2nd laser L2 is changed, the 1st laser L1 and the 2nd laser L2 are penetrated from exit facet as the directional light of its optical axis unanimity, guide to shared object lens 41 by leaded light.Consequently, can accept back light Lr1, the Lr2 that optical axis is in the 1st and the 2nd laser of consistent state with shared photo detector 3.
(other example)
Again, in above-mentioned each example, be to utilize optical element that the 2nd laser is deflected, but also can be opposite, utilize optical element that the 1st laser is deflected.
In addition, in above-mentioned each optical element, be that their plane of incidence side is made stepped surfaces, but also can in contrast exit facet as stepped surfaces, be made tabular surface with the plane of incidence.
Also have, above-mentioned each optical element is that exit facet is made tabular surface, but also can make concave surface or convex surface, to enlarge or to dwindle diameter by light beam.
As mentioned above, the employed leaded light optical element of dual wavelength optical-head apparatus of the present invention, the plane of incidence or exit facet made along optical axis direction step-like differential stepped surfaces, and suitably set the differential of adjacent stations terrace, so that change by the relative angle of this leaded light with the different wavelengths of light of optical element.
As long as leaded light optical element of the present invention because make one face become stepped surfaces, so make simply, can be produced as the formed products of resin material at an easy rate in a large number.Therefore, make optical axis merging with the optical element that uses costliness such as prism from the emergent light of multiple light courcess, perhaps the situation that the light from multiple light courcess after the recording medium reflection is guided to shared photo detector is compared, and can low-cost, small compact make optical system.
In addition, make under the situation of concentric circles, can obtain such advantage: can reduce when being assembled in the optical-head apparatus optical system requirement the positional precision of sense of rotation at each step surface that will constitute stepped surfaces.
Also have, if adopt leaded light optical element of the present invention, because do not use expensive element such as prism, the optical axis of the light that combined light source that a plurality of light sources are housed in the common components penetrates is merged, it is just very convenient to use such combined light source to constitute the optical system of optical-head apparatus.Consequently, compare when using the independent light source that is provided with, each optical element of optical system, the position adjustment of device are just extremely convenient.
Equally,, do not use expensive elements such as prism, just can penetrate and each light beam after recording medium reflects guides to shared photo detector from Different Light if adopt leaded light optical element of the present invention.Therefore, can low-cost, small compact constitute the optical system of optical-head apparatus.
Except above-mentioned effect, if in optical-head apparatus of the present invention, configuration transparent plate element replaces the leaded light optical element, and disposes a light source replacement dual wavelength combined light source, just can constitute optical system in the optical-head apparatus of the single wave length type of generality.Like this, the present invention also can obtain such advantage: can make the optical system structure of this optical system of packing into can be common to dual wavelength shaven head and single wavelength shaven head.
Claims (6)
1. a leaded light optical element that merges or use for these light are guided to shared photo detector for the optical axis that makes in the optical-head apparatus different wavelengths of light that penetrates from Different Light is characterized in that,
This leaded light has the relative plane of incidence and exit facet with optical element,
One of the described plane of incidence and exit facet are stepped surfaces,
The level difference size of each adjacent stations terrace of this stepped surfaces is set at, and only to seeing through a kind of wavelength light in the described different wavelengths of light of these adjacent stations terraces, makes its phase differential that produces n wavelength amount, n=1,2,3 ...
2. leaded light optical element according to claim 1 is characterized in that, described step surface is a curved surface.
3. leaded light optical element according to claim 1 is characterized in that described step surface is made concentric circles.
4. the optical-head apparatus with the described leaded light of claim 1 with optical element is characterized in that,
Have: the 1st light source that penetrates the 1st bundle light, penetrate the 2nd light source of the 2nd bundle light different with described the 1st bundle light wavelength, make the described the 1st and the 2nd bundle light focus on the object lens of the record surface of optical recording media, and by the shared photo detector of described object lens acceptance by the 1st and the 2nd bundle light of the record surface reflection of optical recording media
Described leaded light with the optics arrangements of components on from described object lens to the light path of described shared photo detector, one of the described the 1st and the 2nd bundle light by after the reflection of the record surface of optical recording media is deflected after, this two-beam is guided to described shared photo detector.
5. the optical-head apparatus with the described leaded light of claim 1 with optical element is characterized in that,
Have: the 1st light source that penetrates the 1st bundle light, penetrate the 2nd light source of the 2nd bundle light different with described the 1st bundle light wavelength, make the described the 1st and the 2nd bundle light focus on the object lens of the record surface of optical recording media, and by the shared photo detector of described object lens acceptance by the 1st and the 2nd bundle light of the record surface reflection of optical recording media
Described leaded light with the optics arrangements of components from described the 1st light source and described the 2nd light source to the light path of described object lens, the described the 1st and the 2nd bundle light be at optical axis guide to described object lens under the consistent state.
6. according to claim 4 or 5 described optical-head apparatus, it is characterized in that the described the 1st and the 2nd light source is the combined light source that is contained in the common components.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP206922/2000 | 2000-07-07 | ||
| JP2000206922A JP3860953B2 (en) | 2000-07-07 | 2000-07-07 | Optical head device |
| JP206922/00 | 2000-07-07 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1337688A CN1337688A (en) | 2002-02-27 |
| CN1196123C true CN1196123C (en) | 2005-04-06 |
Family
ID=18703766
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNB01122360XA Expired - Fee Related CN1196123C (en) | 2000-07-07 | 2001-07-03 | Optical-head device |
Country Status (3)
| Country | Link |
|---|---|
| US (1) | US6961297B2 (en) |
| JP (1) | JP3860953B2 (en) |
| CN (1) | CN1196123C (en) |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20030147331A1 (en) * | 2002-02-07 | 2003-08-07 | G-Bond Optoelectronics, Inc. | Optical pickup diffracting one of two laser beams to a single detector |
| JP3837089B2 (en) * | 2002-06-07 | 2006-10-25 | 松下電器産業株式会社 | Diffraction element and optical pickup head device |
| CN100361214C (en) * | 2003-04-28 | 2008-01-09 | 松下电器产业株式会社 | Optical head and optical disk device |
| WO2005083694A1 (en) * | 2004-02-27 | 2005-09-09 | Konica Minolta Opto, Inc. | Object optical system, optical pickup device and optical information recording/reproducing device |
| JP2005327403A (en) * | 2004-05-14 | 2005-11-24 | Sony Corp | Optical pickup and optical recording medium recording and reproducing device |
| KR101312633B1 (en) * | 2007-04-04 | 2013-10-04 | 삼성전자주식회사 | Hologram optical device and compatible optical pickup and optical information storage medium system employing the same |
| CN110178058A (en) * | 2017-01-18 | 2019-08-27 | 日本板硝子株式会社 | The manufacturing method of optical component and optical component |
Family Cites Families (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0834532B2 (en) * | 1990-05-15 | 1996-03-29 | キヤノン株式会社 | Color image reader |
| US5666344A (en) * | 1991-06-04 | 1997-09-09 | International Business Machines Corporation | Multiple data surface optical data storage system |
| JP3240846B2 (en) | 1994-08-12 | 2001-12-25 | 松下電器産業株式会社 | Light head |
| KR100214046B1 (en) * | 1995-03-27 | 1999-08-02 | 마츠시타 덴끼 산교 가부시키가이샤 | A super-resolution optical head device |
| US6449237B1 (en) * | 1996-08-29 | 2002-09-10 | Samsung Electronics Co., Ltd. | Optical recording and pickup head for digital versatile disc compatible with read-writable compact disc by adopting flat plate lens having staircase type diffraction grating structure |
| JP3653923B2 (en) * | 1997-03-19 | 2005-06-02 | ソニー株式会社 | Recording / reproducing apparatus and method |
| JPH10334504A (en) * | 1997-05-29 | 1998-12-18 | Nec Corp | Optical head device |
| JP3640059B2 (en) * | 1999-02-12 | 2005-04-20 | パイオニア株式会社 | Aberration correction apparatus and optical apparatus using the same |
-
2000
- 2000-07-07 JP JP2000206922A patent/JP3860953B2/en not_active Expired - Fee Related
-
2001
- 2001-07-03 CN CNB01122360XA patent/CN1196123C/en not_active Expired - Fee Related
- 2001-07-06 US US09/900,308 patent/US6961297B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| US20020051421A1 (en) | 2002-05-02 |
| JP3860953B2 (en) | 2006-12-20 |
| CN1337688A (en) | 2002-02-27 |
| JP2002025099A (en) | 2002-01-25 |
| US6961297B2 (en) | 2005-11-01 |
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Owner name: NIDEC SANKYO CORP. Free format text: FORMER NAME OR ADDRESS: SANKYO SEIKI MFG. SEISAKUSHO K.K. |
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Address after: Nagano Patentee after: Sankyo Seiki Seisakusho KK Address before: Nagano Patentee before: Sankyo Seiki Manufacturing Co., Ltd. |
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Granted publication date: 20050406 |